Rotary brushes



L. M. BALLARD l ROTARY BRUSHES Filed De. 22, 1952 Feb 26, 1957 A JNVENTOR. Lou/s M. BALL/1,90,

AI llllllallllllllllllllllnllll TroQA/Ey.

United States Patent@ ROTARY BRUSHES -Louis M. Ballard, Duarte, Calif., assignor to Wayne Manufacturing Company, Pomona, Calif., a corporation of California Application December 22, 1952, Serial No. 327,393

v 4 Claims. (Cl. 15-182) mounting, which minimizes the possibility of damage to their mounting portions in use.

Structurally, a brush embodying the invention includes a rotatable essentially cylindrical rigid body about which is carried a tubular bristle mounting member containing a helical groove into which the bristles are fastened. The bristles are of the looped or U-shaped type, having inner looped portions receivable within the helical groove. An elongated wire-like element extends along the groove and through these looped portions of ythe bristles, and is fastened at its opposite ends to the brush body to positively retain the bristles in the groove.

In order to assure most effective gripping of the bristles,

. I prefer to formthe helically |grooved member of a resiliently deformable material, yso that the groove walls are slightly deformable as the bristles are moved into position, and then act to tightly embrace the bristles in a manner positively preventing their accidental dislocation. At

the same time, such resilient-formation of the grooved body acts to-cushion the bristles, and permit slight movement of their looped base portions, to minimize the possibilities of damage to those portions of .the bristles.

Further, the resilient body is desirable by reason of its capacity for deforming rather than breaking upon engagement with an object, as for instance where the brush is used as astreetsweepersand@ is calledlupon, to handle a board or other article encountered inthe street.

The most desirable material for forming the grooved memberis rubber, ApreferablyV of the type used in automobile tire treads, When` rubber is used, it has the advantage of being'able to withstand damage from water or other deteriorating substances which `may be Vmet in use. The VrubberniayV be molded and cured while in position about the brush body, so lthat the curing process acts to vulcanize the rubber to the body. In order to maximize the elfectiveness of lthe vulcanization bond thus formed between the rubber and body, the outer surface of the body may be roughened as by sand blasting, prior to application of the rubber.

The above and other features and objects of the present invention will be better understood from the following detailed description of the typical embodiment illustrated in the accompanying drawing, in which:

Fig. 1 is a side view, mostly in section, of a rotary brush constructed in accordance with the present invention;

Fig. 2 is a view taken along line 2-2 of Fig. 1; and

Fig. 3 is an enlarged fragmentary section taken in the ICC Patented Feb. 2.6, 1957 plane of'Fig. 1- and showing an endportion of the brush.

Referring first to Fig. 1, the illustrated brush includes a hollowcylindricalrigid body or drum 11, about which is carried a tubular bristle mounting member 12. VThe wall of body 11 is preferably imperforate, and formed of a suitable rigid metal, as for -instance steel. Bristle mounting member 12 is`made"of a resiliently deformable material, preferably rubber. This rubber forming member 12 maybe approximately the same as that utilized in'automobile tire treads, preferably between about 70 'and 80 v Shore, and for best results about 75 Shore.

position about body 11 so. that the rubber is vulcanized Vdirectly to the cylindrical outer surface of the body.

For lthisre'ason, the raw rubber mayiirst be extruded onto the outer `surface of body 11, following which the body and rubberare placed` in a mold having a configuration corresponding to' the desired shape of the rubber body A12, and heat and .pressure may Vthen be -applied-to the rubber to cureit and vulcanize it to the body. Before 4 applica'tion'ofthe raw rubber Kto the outside of body 11, I lind. it desirable to roughenl the outer cylindrical surface Aof body 11, as vby sand blasting it, to assure the formation 'of an effective vulcanization bond between the rubber and rnetal.

The rubber :shaping mold is so designedas to form'in the outer surface of body 12 a helical-outwardly facing .groove or recess-13, extending about and along the rubber body'for -its entire axial extent. This recess may be essen- `tially rectangular in cross-section, and preferably is substantially square.

The Sbristles 14 aretof the looped or essentially U- shaped, type, each having two ends at the outer extremity k'l5-of the brush, and being shaped to extend radially inwardly .from one of those ends into groove 13, and then -be curved back outwardly toward its second end. Each of the bristles thushas a looped portion 16 received'within the helical groove 13 in the bristle mounting member. An elongated liexible retaining element 17, preferably a wire or metal cable, extends helically about member 12 within its groove 13, and through the inner looped portions of all ofthe bristles 14, to tightly retain the inner Vattachment to shafts 1S, tubular body 11 may contain at its opposite ends a pair of transversely extending plates 20, having outer axially turned portions 21 welded at 22 to the body. These transverse plates 20 may have central openings 23, at the locations of which the opposite ends of a shaft receiving tube 24 are welded to the plates. Each of the shafts 18 carries a transverse plate 25, which is welded to the shaft at 26, and is removably attachable to one of the plates 20, as by a number of circularly spaced bolts 27.

The end portions of the bristle retaining wire or cablc 17 extend through a pair of registering openings 28 in drum 11 and in the axially turned portions 21 of plates 2t), and are fastened tightly to shaft carried pilates 25. Such attachment of cable 17 to plates 25 may be elfected by passing the cable ends through a pair of metal straps 29 removably attached to plates 25, and forming at the ends of the cable a pair of knots 30 of a size incapable of movement through the retaining straps. The drum ends may be closed koutwardly beyond plates 25 by a pair of transverse plates 31, attached to plates p25 respectively. by a number of circularly spaced screws 32. Screws 32 may be connected directly into threaded bores 33 in the plates 25, with tubular spacers 34 being provided about the screws between plates 31 and 25. A pair of annular rings 35 are desirably welded tothe ends of drum 11, for engagement with transverse end plates 31. Y

Because of the resilience of bristle mounting member 12, the bristles 14 are very positively and eifectively retained against'accidental dislocation. This is true because it isvpossible, when member 12 is of a resilient nature, to form the groove 13 of a'size such that the inner looped portions 16 of the bristles must be forced into the groove. As these looped portions of the bristles are then forced into the grooves, the groove walls are resiliently deformable in a manner permitting accommodation of the bristle loops, and then act to tightly embrace and positively retain those bristle loops after their insertion into position. Further, the resilience of the rubber member 12 permits some deformation of the bristle retaining groove walls in response to forces exerted against the bristles, to provide a somewhat cushioned mounting member for the bristles acting to miniextending helically between successive turns of said groove, said groove and said projecting portion of the member each having an axial dimension about as great as its radial dimension.

2. A rotary brush comprising a rotatable externally essentially cylindrical rigid metal body, a tubular member formed of rubber carried about and bonded to said body and containing a radially outwardly facing groove extending helically about the axis of rotation of said body, bristles having looped inner portions removably received in said groove and projecting outwardly therefrom, and an elongated flexible member extending through said looped portions of the bristles and helically within the groove to removably retain the bristles therein and fastened at its opposite ends to saidbody, said rubber member having a radially outwardly projecting portion extending helically between successive turns of said groove and containing within the interior of said portion and mize the possibility of damage to their mounting por- Y tions. Such resilient deformability of the groove walls may be enhanced by providing in the rubber body 12, and particularly in its helical portion 12a which projects outwardly between successive turns of the groove, an inner elongated air passage or chamber 36 extending helically within the body portion 12a.

A further advantage of the use of rubber or other resilient material in the bristle mounting member 12 is that it prevents damage to this member in the event of engagement with a hard or abrasive object in use. This factor is of extreme importance when the brush is to be used to a rotary street sweeper brush, in which case it may be required to handle various types of hard objects which might break or seriously damage a non-resilient bristle carrier. At the same time, the rubber of member 12 is capable of resisting deterioration by contact with water or other materials which may be encountered in use;

I claim:

l. A rotary brush comprising a rotatable externally essentially cylindrical rigid metal body, a tubular member formed of rubber carried about and bonded to said body and containing a radially outwardly facing groove extending helically about the axis of rotation of said body, bristles having looped inner portions removably received in said groove and projecting outwardly therefrom, and an elongated flexible member extending through said looped portions of the bristles and helically within the groove to removably retain the bristles therein and fastened at its `opposite ends to said body, said rubber member having a radially outwardly projecting portion along substantially its center an elongated helical passage.

3. A rotary brush comprising a rotatable externally essentially cylindrical rigid body, a tubular member formed of rubber carried about said body and containing a radially outwardly facing grooveextending helically about the axis of rotation of said body, bristles having looped inner portions removably received in said groove and projecting outwardly therefrom, and an elongated ilexible member extending through said looped portions of the bristles and helically within the groove to removably retain the bristles therein and fastened at its opposite ends to said body, said rigid body being formed of metal to which said rubber member is vulcanized substantially continuously over the entire area of the rubber member, said rubber member having a radially outwardly projecting portion extending helically between successive turns of said groove and containing within the interior of said portion and along essentially its center an elongated helical passage, said groove and said projecting portion of the member each being of essentially rectangular transverse section, and each having an axial dimension about as great as its radial dimension.

4. A rotary brush comprising a rotatable externally essentially cylindrical rigid metal body, an essentially tubular member formed of rubber carried about and bonded to said body and containing a radially outwardly facing groove extending helically about the axis of rotation of said body, bristles having looped inner portions removably received in said groove and projecting outwardly therefrom, and an elongated flexible member extending through said looped portions of the bristles and helically within the groove to removably retain the bristles therein and fastened at its opposite ends to said body.

References Cited in the file of this patent UNITED STATES PATENTS 1,371,601 Braun Mar. 15, 1921 2,190,206 Churchill Feb. 13, 1940 2,553,748 Carlson May 22, 1951 2,604,362 Sugerman July 22, 1952 2,680,261 Sorensen June 8, 1954 

